Optimizing Set-Up and Adjustment of Crimpers, Sealing Jaws, and Knives

The first two parts of this series explored the potential problems created by end seal wrinkles and creases and ways to eliminate or reduce them on horizontal flow wrappers (Part 1) and vertical baggers (Part 2). In some situations wrinkles or creases are unavoidable, and, even without those issues, most packages have the inevitable transition between multiple film layers created by either a fin or a lap seal. This can make it more difficult to achieve quality seals, and attempts to do so can lead to additional issues:

•Overheating distorts the seal and can cause poor hot tack, where the film springs back open, or “moons,” before the seal can set.

The operating window for creating quality seals can be elusive, resulting in packages that leak or are distorted and either fail to protect the product or have little appeal to consumers.

This post reviews some of the detailed solutions in Greener Corporation’s Knowledge Center that will help you seal over extra layers of film at the end seal by refining the set-up and adjustment of crimpers, sealing jaws, and knives.

Set-up procedures for knives and anvils can vary according to the make and model of the packaging machine, knife adjustment style, and other factors. There are, however, some general principles that make these adjustments more effective and efficient, reducing downtime and parts costs.

♦ Optimize Knife Design

Knives ground on a diagonal, or bias–whether they have a zig zag or a straight cutting edge–require less pressure to cut so they are easier to set up and typically last longer.

Zig zag knives with smaller (more) teeth are also easier to set up and provide longer life.

Project Goals

The corporate engineering department at a large, international company commenced a project to reduce material costs for a variety of products that are individually packaged on horizontal flow wrappers. Greener Corporation was invited to participate in a series of meetings that defined the project’s initial goals:

To reduce the cut-off length for each package by reducing the overall seal width, thus allowing the product envelope to remain unchanged.

Clearance and pressure settings on horizontal flow wrappers are critical for achieving quality packages, minimizing downtime, and controlling costs. We’ve noticed that the differences between clearance and pressure, and the proper occasions to adjust each of them, are not always clear to those making these adjustments. Greener’s latest “Tech Bites” video and blog post differentiate the function and adjustment of clearance and pressure. Read more

Greener Corporation has published a series of white papers devised to help optimize package quality and productivity on horizontal and vertical form fill seal packaging lines. In addition to helping you solve problems, these technical articles provide foundational information you can use to implement proactive improvements—an approach that helps deter problems from occurring in the first place.

The first video in Greener Corporation’s “Tech Bites” series explains how adjusting backlash on horizontal flow wrappers helps prevent problems such as fractured end seals and premature failure of knives and anvils.